The 23 year-old world No 1 beat Poland’s Sylwia Bogacka by 0.7 points in a nail-biting final at the Royal Artillery Barracks in Greenwich, London.
She had long been favourite to triumph, securing the first medal with a score of 502.9 less than 11 hours after Sir Paul McCartney closed last night’s Opening Ceremony of the Olympics. Fellow Chinese shooter Yu Dan took the bronze medal.
Yi's win continues a very successful year, after winning gold in Munich and silver in London in the International Shooting Sport Federation’s World Cup series.
She fought off 56 rivals, including Malaysian shooter Nur Suryani Mohamed Taibi, who is eight months pregnant.
She finished 34th in the qualification round, but was mainly thankful she did not go into labour during the competition.
“I just prayed that I could get to a labour room,” she said. “I would accept it with an open heart. I am not a normal mummy doing everything slowly.
“The baby is quite fine. She hasn’t made an appearance during training or competition. I told her to behave herself. I felt only three or four kicks during the competition. When she kicked I tried to breathe in, breathe out and make myself calm.”
Bogacka and Yi were tied for much of the final, with small gaps only appearing occasionally in a tense 20 minutes with 10 shots each.
The Pole narrowly beat Yi in this morning’s qualification, despite the Chinese shooter’s near perfect 399 out of 400.
Yi only took up shooting in 2007 after failing to make it in track and field and toying with dancing. But she quickly rose to dominance, winning gold at the 2010 world championships.
Katerina Emmons, the Czech who claimed gold in Beijing, very nearly failed to reached the final after facing a shoot-off for the eighth place, which she won by just 0.3 points.
She finished fourth, a disappointment after winning the Milan event of this year’s World Cup.
But several shooters failed to make the final. Jennifer McIntosh, the youngest member of Team GB's shooting squad finished 36th, shooting 392 out of 400.
The 21 year-old was competing in her first Olympics, after securing two gold medals and a bronze in the 2010 Commonwealth Games.
Germany's decision not to send Sonja Pfeilschifter, the world number two, backfired spectacularly when their top-ranked shooter, world number seven Jessica Mager finished 20th.
